William Clark was born on August 1, 1770. He grew up on his family's
Virginia plantation, but moved to Louisville, Kentucky when he was 14.
In 1789, he joined the militia to fight the Native Americans in the Ohio
Valley. Three years later, he joined the army and became an officer, only
to retire in 1796 to manage his family's plantation.

In 1803, Clark's army comrade, Meriwether Lewis, invited Clark to co-lead
an expedition across President Thomas Jefferson's Louisiana Purchase. To
prepare for the trip, Clark studied astronomy and cartography. He was responsible
for the expedition's record keeping and map making.

After Clark successfully returned from the expedition, Jefferson appointed
Clark principal Indian agent and brigadier general of the militia for the
Louisiana Territory. In 1813, Clark became governor of the Missouri Territory.
When Missouri became a state in 1820, Clark unsuccessfully ran for governor,
but continued to focus on Native American affairs. This experience helped
him become Superintendent of Indian Affairs, a position that he held from
1822 until his death on September 1, 1838.